Python 3.7 support: async is a keyword

[hroncok]

According to PEP 492, async and await are now keywords and cannot be used as names.

psycopg2 does:

  File "/usr/lib64/python3.7/site-packages/psycopg2/tests/test_async_keyword.py", line 43
    self.conn = self.connect(async=True)
                                 ^
SyntaxError: invalid syntax

  File "/usr/lib64/python3.7/site-packages/psycopg2/tests/test_cursor.py", line 570
    connect_func = lambda: self.connect(async=True)
                                            ^
SyntaxError: invalid syntax

Can this be renamed, to asynch maybe or async_?

[dvarrazzo]

It is already fixed: since psycopg 2.7 you can use async_ instead. The tests should probably be fixed (at the moment Python 3.7 is not in travis) but the lib itself should work.

[hroncok]

Running on Travis CI to see what happens BTW: https://travis-ci.org/hroncok/psycopg2/jobs/380610023

[hroncok]

hroncok@fcd97d0

[hroncok]

Would you accept a PR that fixes the tests and enables 3.7 on Travis?

[hroncok]

Funny enough the tests pass as they are.

[dvarrazzo]

test_async_keyword.py, as the name says, is conditionally excluded from the test suite, see tests/__init__.py. test_cursor.py seems broken and can be changed using async_.

[dvarrazzo]

Of course I'm happy to accept running the tests on 3.7 too, thank you :)

[dvarrazzo]

Weird the tests pass as they are. I would have expected test_cursor to fail importing.

[hroncok]

ef64493

[dvarrazzo]

As of 2.7 the tests were passing on python 3.7. The cursor test was broken in psycopg 2.7.2 by b203a7c

[dvarrazzo]

ef64493

this is in master but not in maint_2_7. Will cherry-pick.

[hroncok]

Thanks a lot. I've added 3.7 to Travis in #715

This issue can be considered invalid:

• test_cursor was fixed in ef64493
• test_async_keyword is skipped

[dvarrazzo]

test_cursor fixed too. However 3.7 tests cannot run automatically on the branch maint_2_7 because it still supports Python 3.2, which instead is no more supported by recent pip versions (see this failure).

That's no big deal: I'd start push psycopg 2.8 instead.

[P-EB]

@dvarrazzo Debian migrated to python 3.7 in unstable. Do you have an ETA for 2.8? :)

Cheers!

[dvarrazzo]

No, no release date yet, working on a couple of experimental branches.

However psycopg 2.7.5 runs perfectly well on python 3.7: try

$ make PYTHON=/usr/local/py37/bin/python3
$ make PYTHON=/usr/local/py37/bin/python3 check

[df7cb]

At the moment, installing python3-psycopg2 2.7.5-1+b1 on Debian unstable explodes: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=902715

[hroncok]

See https://src.fedoraproject.org/rpms/python-psycopg2/c/89f4b65570783ea763c37311e974296d3ff40d90?branch=master for how we dealt with it within Fedora.

[olasd]

Thanks @hroncok for the pointer; I've done mostly the same thing when uploading an updated psycopg2 that fixes the install issue in Debian.

FWIW, @dvarrazzo, the concrete issue here is that when installing Python modules, Debian will byte-compile all files for all supported versions, even if they're never imported. The test_async_keyword.py file can't be byte-compiled by 3.7 (because it uses async as a variable), so the install blows up. The "fix" is to stop shipping the file in the binary packages.

Thanks for maintaining psycopg2, and sorry for the noise :)

[sammy-tam]

Thanks a lot. We have similar case where in our exist pipeline where we will manually compile all files with python3 -m compileall . and deploy the *.pyc only. Our current workaround is to remove the test_async_keyword.py before compiling